


Fun-Sized

by magisterpavus



Category: Voltron: Legendary Defender
Genre: Declarations Of Love, Established Relationship, Galra Shiro (Voltron), Knotting, M/M, Rough Sex, Size Difference, tummy bulge
Language: English
Status: Completed
Published: 2018-12-23
Updated: 2018-12-23
Packaged: 2019-09-25 06:57:42
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,092
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17116586
Author URL: https://archiveofourown.org/users/magisterpavus/pseuds/magisterpavus
Summary: Galra, as a rule, are big.Keith is well aware of this fact, but bent over the pilot console with Shiro crushing him against the warm metal and fucking him from behind in devastating thrusts that threaten to break Keith apart at the seams, he thinks he never quite grasped the full meaning of it before Shiro.





	Fun-Sized

**Author's Note:**

> please know that the google doc title for this story is just "him big" and I think that sums it up.
> 
> This fic is inspired by @Jotakorium's galra!shiro AU. [please give 'em all the love on twitter](https://twitter.com/Jotakorium) also i've been thirsty for galra since day 1 we all been knew about that. it was only a matter of time.

Galra, as a rule, are big. 

Keith is well aware of this fact, but bent over the pilot console with Shiro crushing him against the warm metal and fucking him from behind in devastating thrusts that threaten to break Keith apart at the seams, he thinks he never quite grasped the full meaning of it before Shiro. 

As Krolia never fails to point out, Keith is very small for a half-Galra. And Shiro is large even for a Galra. Keith’s head comes up to barely Shiro’s mid-torso if he’s lucky, on his tiptoes, maybe mid-chest. They often bonded over how they had been outcasts among the other Galra based upon their abnormal sizes, though the expectations placed upon them were quite different – Keith was seen as fragile, too little to be of any use in a fight; Shiro was seen as not much more than a tank, good only at violence and force. In reality, Keith is, according to Kolivan, one of the best fighters the Blade has ever seen, with unmatched dexterity and an iron will, and Shiro is a tactical genius who would be perfectly happy if he never had to use force to solve his problems.

Like two sides of the same coin, they understand each other, and have undertaken some of the Blades’ most victorious missions together. They know how the other ticks, and Keith won’t speak for Shiro, but he trusts Shiro with his life, and Keith’s trust is not easily given. With Shiro though, it’s earned, a million times over. And not just on the battlefield.

Now, pinned under him, Keith feels smothered in the best way, and closes his eyes at the thought of how wide Shiro’s cock must be stretching him, forcing him open, wrecking him until he’ll feel it for days, every time he shifts in the pilot seat or lunges into battle –  _ fuck. _ It’s a lingering, familiar pain he craves more often than not these days, and Shiro has no complaints about his insatiability. 

Still, Shiro maintains a degree of constant caution, and Keith is hyper-aware of it, feels him holding himself back, keeping his pace slow and shallow enough that he never quite bottoms out, never goes as deep nor fast as he could. It’s probably a good idea, all things considered, but Keith wishes desperately that he would let go completely, because if Keith is anything, he is self-sabotaging. 

Shiro’s breath huffs hot and damp against the back of his neck, and when sharp fangs scrape over the tender skin there Keith opens his eyes to bleary slits and moans, arching up into it and scrabbling uselessly at the metal with nails turned claw. The console lights up with a hundred error messages, and Shiro’s panting turns to laughter, low and husky on the shell of Keith’s ear. 

“Careful, my heart, or we will get lost in deep space because you,” he nips Keith’s earlobe enough to sting, “couldn’t control yourself.”

Keith kicks blindly backwards in retaliation and is rewarded with Shiro’s rumbling growl and claws digging into his wrists and hips, holding him fast. “I can’t,” Keith gasps, voice muffled, “not with you.”

The growl shifts to an approving purr. “No? Why not?” His cock rocks in and out of Keith’s arching body, wrenching sensation from him on each plunge inwards, but not enough, never enough. Shiro’s hold on him is firm but playful; Keith could break it if he wished, though he can think of nothing he wants less. 

“I – you’re –”

Shiro hums and noses into his throat, inhaling his scent and rolling his hips a little faster, enough to jerk Keith against the console with every movement and fill the cockpit with the filthy wet squelch of lube and thick Galra precum, which Keith feels dripping hot and slow down the backs of his thighs. “I’m…?”

“Shiro,  _ please, _ I want –  _ ah!” _

Shiro bites down on the join of his neck and shoulder, massive teeth digging in hard enough for fear to spiral cold and dizzying down Keith’s spine the moment before Shiro thrusts in fully with a breathy groan, burying his cock and swelling knot inside as Keith twitches into instantaneous orgasm, nearly mashing his face against the console keys. He’s stopped by claws yanking his hair back, holding his head up to the cool air as he reddens, moans, and comes over Shiro’s flexing thighs, crumpling forward when Shiro pumps him full in turn. 

Shiro waits for him to come down from the blissful high, tugging Keith gently backwards to settle in his lap as he slumps back in the pilot seat. Keith turns his face into Shiro’s throat and licks away the sweat gathering there in the teasing, kittenish way he knows Shiro is weak for. 

Sure enough, Shiro purrs and wraps an arm around Keith’s front, cradling him closer, and that’s when they notice it – Keith’s belly, normally flat and lean with compact muscle, bulges outwards just enough for them both to freeze.

Keith’s breath shortens. “Oh,” he whispers. “Oh, no fucking way –”

Shiro is trembling, almost violently so, as his huge palm settles over the slight distension. “That is,” he starts, and stops, audibly stuttering. “Keith, are you – does this not hurt you?!”

Keith stares down at it, at the shape of Shiro’s cock inside of him. “No,” he says, voice sounding distant even to his own ears. “No, it’s – Shiro, that’s _you._ _Look at you.”_

“Look at  _ you,” _ Shiro retorts, ragged and frantic in a way Keith has never heard from him before. “You’re so small, and yet – you take all of me, everything I have, and demand  _ more, _ how –”

_ “Yes,”  _ Keith breathes, heart pounding, “Shiro, yes, I want more, all that you would give me, all that you  _ could _ give me –”

“No,” Shiro gasps, burying his face in Keith’s bitten shoulder, “no, I will break you, I  _ cannot, _ you don’t know what you ask –”

“Then show me,” Keith hisses, and twists in his lap, on his cock, clenching around the knot plugging him full until Shiro snarls and tries to force his hips still, but Keith resists, grinding down, mouth falling open when Shiro’s softening cock responds to the ceaseless stimulation, rehardening in the relentless heat of Keith’s body, stretching Keith anew. His chest heaves against Keith’s back, struggling to contain his strength as he always does.

“I will hurt you,” Shiro warns, shuddering as Keith ignores him and continues to goad him into action. “Humans are not meant to –”

“I’m not human,” Keith snaps over his shoulder, baring needle-sharp teeth, eyes flashing gold. “I’m Galra, and Shiro, I’m  _ yours.” _

Poor Shiro never stood a chance, and Keith knows it.

Shiro roars, and all but rips Keith off of him, sudden emptiness shocking him into pliancy; even more shocking is the complete and impossible fullness as Shiro stands, glowing eyes glaring down at him, and impales Keith on his entire cock in one fluid slide, holding Keith up with a single hand and driving into him with delicious force. 

Keith chokes on spit; Shiro is using his body mercilessly, thighs slapping against Keith’s ass as he lifts him higher, splitting Keith open until all he sees are blurry white sparks and all he feels is an aching, throbbing  _ burn _ verging on too much, yet it satisfies him even as it destroys him. 

Shiro pitches forward unexpectedly and Keith falls back, directly onto the console, the edge digging harshly into the small of his back, spread legs hitched high, ankles barely reaching Shiro’s broad shoulders. Shiro’s ears are flattened against his skull, mouth hanging open, tongue lolling, eyes alight with something fierce and primal that rocks through Keith like a tidal wave, ebbing and flowing as Shiro takes him apart. The cum already inside of Keith moves with Shiro’s cock, spilling out and soaking his inner thighs and ass, and the Galra above him growls, moving somehow faster, harder, his gaze on Keith intent. 

What the intent is, Keith isn’t totally sure. He’s hoping it’s to fuck him until he passes out, which at this rate will be very soon. 

Keith’s cock bounces against his bulging belly, leaking with every pound to his prostate, balls drawn up tight and full but unable to spill, because Shiro has not touched him; he offers nothing but the faint friction of the thick hair leading down to his cock, and Keith shouts as coarse fur rubs against him, only to cry out when Shiro changes the angle and reaches down to pluck at Keith’s nipples with curved claws until they are perked and swollen and tears are running down Keith’s face as he squirms uselessly underneath Shiro’s bulk. 

Hairs rise all over Keith’s body when Shiro rubs the pads of his thumbs over Keith’s sensitive nipples; he twists to get away from the overwhelming touch but there is no escape, and his breath punches from his lungs in rasping gasps of Shiro’s name, pleas, maybe; to stop or to continue into oblivion, or both. His heart thuds and comets streak across the blank black of the ceiling, and further, into the void of space just beyond the glass, limitless, so vast Keith is breathless at the thought. 

Drool pools on the metal and Keith is barely aware of it, just as he is barely aware of the strain in his thighs, the claws raking raised pink lines over his ribs, the cock pulsing deep in him; everything edges on numb ecstasy, nothing and everything all at once.

Shiro’s knot presses hard at his aching rim, a welcome threat, and Keith’s head lolls in surrender, eyes unseeing, mouth lax when Shiro bows over him and kisses him sloppy and thorough, a claiming of sharp teeth and twisting tongue that could plunge down Keith’s throat if Shiro wanted to. 

“Mine,” Shiro gasps as he pulls away, fucking Keith raw and relentless. 

Staring up at him, Keith swears it is like the very first time all over again; Shiro held him in his lap in their bed and kissed his neck, his cheeks, his brow, his lips, and promised Keith he would never leave him while his cock sank home. This is rougher, yes, and wilder, uninhibited, but it is an echo of the same, the same longing, the same devotion, the same Shiro, and Keith comes at the thought, taking them both by surprise.

Shiro groans and bends Keith in half when he knots for the second time, a brief burst of heat and vivid, explosive hurt and then the sweet warm fullness of completion. Shiro half-collapses on top of him, and Keith closes his eyes, reduced to a collection of pins and needles in a vaguely humanoid shape. Moving is something Keith might have been able to do once, but no more. That’s okay. Lying here in an inert heap of residual endorphins under Shiro for the rest of eternity sounds just fine to him. 

Except Shiro is moving, murmuring soft and worried over Keith’s skin, lips and fur brushing like so many moth wings, delicate and fleeting. He’s saying words, but Keith’s mind is a dull haze of soothing static, and to listen to Shiro would take far too much effort. Instead, Keith relearns how to speak and mumbles, “Love you,” and Shiro stills above him so completely one would think Keith physically struck him. 

“Keith,” Shiro whispers, cupping his face in a hand that could crush Keith’s skull, but never would,  _ “Keith.” _

And Keith realizes that’s the first time he’s ever said it. In his defense, Galra are creatures of few words. Actions are considered more important, more meaningful. But Keith wants to share those words with Shiro, to tangle their meaning up with Shiro’s name, so that every time he thinks, _ I love you, _ he thinks of Shiro, and feels what he feels now in this precious moment drawn thin as thread between them, wrapped up in Shiro, helpless in every sense of the word, convinced more than he has ever been before that this is where he is meant to be, and who he is meant to be with.

“I love you,” Shiro whispers back, his eyes wide, shining suns bathing Keith in adoring radiance that sinks to his core. “So much, Keith. So, so much.”

Keith sighs and closes his eyes, sleepy and content, and Shiro says, “Let me take care of you,” and Keith nods, reaches up blindly, and Shiro takes his hand, gathering him close in an embrace that sates an entirely different need Keith never knew he had. 


End file.
